INFO: task syz.2.6540:30286 blocked for more than 143 seconds. Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.6540 state:D stack:25488 pid:30286 tgid:30282 ppid:28686 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 nfsd_nl_version_get_doit+0x181/0x790 fs/nfsd/nfsctl.c:1848 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:713 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:728 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2568 ___sys_sendmsg net/socket.c:2622 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2654 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f62d898cda9 RSP: 002b:00007f62d9758038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f62d8ba6160 RCX: 00007f62d898cda9 RDX: 0000000024000100 RSI: 0000000020001740 RDI: 0000000000000009 RBP: 00007f62d8a0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f62d8ba6160 R15: 00007ffec2ed7a68 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e9387a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e9387a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e9387a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by kworker/u8:6/3409: #0: ffff8880b863e798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606 #1: ffff8880b8728948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987 2 locks held by getty/5581: #0: ffff888035d720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by kworker/1:1/23651: #0: ffff8880b863e798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606 #1: ffff8880b8728948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987 6 locks held by kworker/1:3/27196: #0: ffff888141ac2948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888141ac2948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90005397c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90005397c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffff8881453a6190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #2: ffff8881453a6190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5851 #3: ffff88804545b190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #3: ffff88804545b190 (&dev->mutex){....}-{4:4}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1005 #4: ffff88807c3dd160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #4: ffff88807c3dd160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1005 #5: ffffffff8fc3b528 (register_mutex#6){+.+.}-{4:4}, at: usb_audio_probe+0x417/0x2100 sound/usb/card.c:813 2 locks held by syz.0.6084/28558: #0: ffffffff8fd10b70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec02b08 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12d/0x1a90 fs/nfsd/nfsctl.c:1922 2 locks held by syz.2.6540/30286: #0: ffffffff8fd10b70 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec02b08 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x181/0x790 fs/nfsd/nfsctl.c:1848 1 lock held by syz.1.6876/31616: 1 lock held by syz.9.6884/31651: #0: ffffffff8e93db40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3741 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111